Social Effects Large-scale internal migration and rapid urbanization are among the most important social effects of rapid population growth. The growing numbers of children who survive their parents place new strains on intergenerational relationships. Social mobility is impeded by continuing widespread poverty. Because only a fraction of the growing population can be absorbed into the modern sector, the numbers of people in the traditional sector rapidly increase and the gap between the two continually widens. Thus two "nations," one relatively well off and the other backward and poor, exist side by side in the same country. Political Effects Political and social conflicts among different ethnic, religious, linguistic, and social groups are greatly worsened by rapid population growth. Political and administrative stresses are increased by the rural-urban migration which is partly caused by this growth, and by increasing demands for government services in health, education, welfare, and other functions. The large proportions of young people, particularly those who are unemployed or have little hope for a satisfactory future', form a disruptive and potentially explosive political force, although there is no evidence that rapid population growth is by itself the cause or even the major contributing factor in violence and aggression. Consequences for Education Because the numbers of children grow even more rapidly than the total population, the need for educating ever larger numbers inhibits the raising of enrollment ratios and improvement in the quality of education. High proportions of children reduce the amount out of any given educational budget that can be spent for the education of each child. Because each cohort, or age group, of the population is larger than its predecessor, it is difficult to recruit sufficient numbers of teachers from among the adult population. Health, Welfare, and Child Development The cost, adequacy, and nature of health and welfare services are affected by rapid population growth in much the same way as are those of educational services. In the individual family, maternal death and illness are increased by high fertility, early and frequent pregnancies, and the necessity of caring for excessive numbers of children. The physical and mental development of children is often retarded in large families because of inadequate nutrition and the diseases associated with poverty, and because the children are deprived of sufficient adult contact. Poor and crowded housing in the urban slums of ranidlv growins cities oroduces further illness and retardation.